Influenza A(H5N1) Virus Infections in 2 Free-Ranging Black Bears (<i>Ursus americanus</i>), Quebec, Canada
Bibliographic record
Abstract
S ince its arrival in North America during De- cember 2021, the Eurasian highly pathogenic avian influenza (HPAI) virus subtype H5N1, clade 2.3.4.4b, has been associated with a high mortality rate for wild birds all over the continent (1).Affected bird species include mainly waterfowl and colonial nesting marine birds, as well as scavenger birds, such as gulls, eagles, vultures, and corvids (2,3).As with several other subtypes, HPAI H5N1 can potentially infect persons, although clinical cases in humans have been limited (4).However, this virus has been shown to be pathogenic for different species of wild mammals, including red fox, striped skunk, mink, raccoon, and seals (5-7).Infections with influenza A(H1N1) viruses have been described in captive sloth bears (8).We report and describe infections by HPAI H5N1 virus in 2 black bears (Ursus americanus) found in Quebec, Canada, during the summer of 2022. The StudyTwo young-of-the-year black bear cubs (likely born in January-February) were observed wandering on a road within the Forillon National Park in Gaspé, Quebec, Canada (48°51′39′′N, 64°13′26′′W), on June 14, 2022.The cubs, which were active and quite vocal, were not attended by their dam.Shortly afterward, an adult female bear with unusual behavior was reported ≈200 m from the cubs.This female was wandering between vehicles, fell into a river, and began circling.Upon the arrival of park officials, the animal was in lateral recumbency and convulsing in a ditch.Because of the severity of the neurologic signs present and concern for public safety, the bear was anesthetized and then euthanized.The 2 cubs, presumed to be orphaned, were also euthanized.The carcasses of the adult female and 1 of the cubs were subsequently frozen.The adult female was thawed a few days later and examined on site.Different organs were sampled, refrozen and shipped, along with the originally frozen cub, to the Canadian Wildlife Health Cooperative Quebec regional center for further macroscopic examination, which was performed on July 7, 2022.Macroscopic examination of viscera of the adult female show no notable findings, other than extensive postmortem changes.The cub (a 5.1-kg female) was thin and had limited fat stores.A mild mesenteric lymphadenomegaly was present, and the cerebrum appeared to be diffusely congested.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".